Construction of roadways, footways, and the like.



R 923.195 .EX

UNITED STATES PATENT OFFICE.

GEORGE ARTHUR MITCHELL, ARTHUR JAMES MITCHELL, AND ERNEST EDWINMITCHELL.

OF LONDON, ENGLAND, ASSIGNORS TO THE ROADAMANT COMPANY, LIMITED, OF LON-DON, ENGLAND.

CONSTRUCTION OF ROADWAYS, FOOTWAYS, AND THE LIKE.

Specification of Letters Patent.

Patented June 1, 1909 Application filed February 16, 1909. Serial No.478,168.

To all whom it may concem:

Be it known that we, GEORGE ARTHUR MITCHELL, of 192 Barry Road, EastDulwich, London S. E., England, builder, Anrnnn JAMES MITCHELL, of TheWillows, Station Road, Crayford, London, England, quantity-clerk, andEnxssr Enwnx' MITCHELL, of 80 Henslowe Road, East Dulwich, London, S.E., England, builder, have invented certain new and useful ImprovementsRelating to the Construction of Roadways, Footways, and the Like, ofwhich the following is a specification.

This invention relates to roadways, footways, courtyards, tennis courts,stair heads, landings, and the like and has for object to provide adurable, dustless and non-slippery facing or covering capable ofwithstanding extremes of heat and cold.

In the specification of previous Letters Patent No. 876377 dated Janna14, 1908 we described a method of producing a road or like surface ofsuch a general nature by heating certain constituents therein specifiedtogether with soda and applying the mass in the plastic condition toform the surface of the road or the like.

As the result of extensive experimentation upon the composition of theprior patent we have found that it is possible to obtain a product whichis superior to that of said patent in a marked and unexpected degree, byemploying the materials and proportions following which must not besubstantially departed from Fine hard stone, 0. g. finely brokengranite--- 30. parts Asphalt 58. 75 Bitumen l. 25 Hydraulic cement, e,9. Portland 7 4 Soda, (1'. e. ordinary washin soda, crystal- Chalk orother mineral carbonate and friable gritty material, e. g., cockle shellor breeze 2. 0 To which may be added, asbestos 1 The bitumen should befirst heated in a caldron, the asphalt then added, and as soon as thishas become thoroughly melted the broken granite or fine stone isintroduced and intimately mixed with the molten mass. The cement,asbestos, soda, chalk and shell or breeze, previously well mixed, arenow added and the mixture is well stirred, raised to boiling point andallowed to simcases also the Want stirred in WlGll the mass 15thoroughly melted.

As above indicated other hard stone of the district, say flint, may beused instead of granite, and in place of chalk another mineral carbonatesuch as magnesian limestone or dolomite may be used. Moreover theasbestos may in some cases be safely omitted.

When the material has been laid in mastic form the soft surface ispreferably sprinkled with sand, which is rubbed in, and this rubbingprocess incidentally removes any blowholes which may form on thesurface.

What we claim and desire to secure by Letters Patent is 1. A coveringfor roadways or other surfaces comprising fine stone, asphalt, bitumen,hydraulic cement, soda, mineral carbonate and friable ritty material inapproximately the relative proportions of 3000 parts of the first, 5875parts of the second, 125 parts of the third, 740 parts of the fourth, 50parts of the fifth and 200 parts together of the sixth and seventh,substantially as described.

2. A covering for roadways or other surfaces consisting of fine stone,asphalt bitumen, hydraulic cement, soda, asbestos, mineral carbonate andfriable gritty material in approximately the relative proportions of3000 parts of the first, 587 5 parts of the second, 125 parts of thethird, 740 parts of the fourth, 50 parts of the fifth, 10 parts of thesixth and 200 parts to ether of the sevgnth and eighth, substantial y asdescribed.

3. A covering for roadways or other sui faces, consisting of fine stone,as broken 3 granite, 3000 parts, asphalt 5875 parts, bitumen -parts,Portland cement, 740 parts,

examines signed our names in the presence of two sub- 10 scribingwitnesses.

GEORGE ARTHUR MITCHELL. ARTHUR JAMES MITCHELL. ERNEST EDWIN MITCHELL.

Vitnesses FREDERICK VVILLIAM BEUER, ROBERT MILTON SPEARPOINT.

